Japanese Patent Application Publication No. 2010-263716A (hereinafter, referred to as “Document 1”) discloses an example of a power device configured to drive a solid-state light-emitting element. This conventional device includes: a switching regulator including a smoothing capacitor in an output stage thereof; and connectors that are inserted between the smoothing capacitor and an LED module as a load to be detachably attached to each other, thereby detachably connecting the LED module with the smoothing capacitor. The connectors are designed to disconnect the smoothing capacitor from the switching regulator when the LED module is disconnected from the switching regulator by separating the connectors. The conventional device thereby therefore can avoid an excess voltage (no-load voltage) from being applied across the smoothing capacitor.
However, in the conventional device of the Document 1, there is a concern that an excess voltage is generated across the smoothing capacitor if the connectors are incompletely (incorrectly) connected with each other (so-called in a “loose-contact” state), because the smoothing capacitor is not completely disconnected from the switching regulator in this state. Then, if the connecters are connected completely (correctly) after the loose-contact state, the excess voltage (which is higher than the voltage in a normal state) generated across the smoothing capacitor is applied to the LED module, thereby causing an excess current to flow through the LED module.
In order to resolve the above problem, it may be considered to add a monitoring means for monitoring the output (voltage/current) of the drive device to detect presence of “a defect in connection” such as the loose-contact state and the no-load state. However, this configuration requires the monitoring means (such as a resistor) for monitoring the output (voltage/current) of the drive device, and therefore there is a problem that the circuit configuration becomes complex to cause an increase in production cost. In addition, in this configuration, part of the output of the switching regulator is dissipated by the monitoring means.